1. Field of the Invention
This invention relates to a plate-making sheet for being printed with stamp characters to be engraved on the stamping face of a stamp, in parallel with a process for making the stamp, mainly for permitting checking of the stamp characters and for indication of the stamp characters on the back surface of the stamp, and a printing device for printing the stamp characters on the plate-making sheet.
2. Prior Art
Conventionally, a stamp making apparatus has been proposed e.g. by Japanese Laid-Open Patent Publication (Kokai) No. 6-278350, which makes a stamp from a stamp body having a stamping surface formed of an ultraviolet curing resin. This apparatus uses an ink ribbon as an exposure mask, and a printing paper ribbon which corresponds to the above-mentioned plate-making sheet. The two ribbons, placed one upon the other, are in the form of a roll wound about a supply reel. The stamp making apparatus has a printing block including a print head and a platen roller. The ink ribbon and the printing paper ribbon are rolled out from the supply reel by the platen roller and guided to the print head which prints stamp characters simultaneously on the ink ribbon and the printing paper ribbon (by transfer of ink). Thereafter, the ink ribbon is advanced to an exposure device facing the stamp body set in the apparatus, while the printing paper ribbon is discharged from a take-out slot of the apparatus. A stamp character label is peeled off the printing paper ribbon and cut or trimmed properly. Then, the label is affixed to the back surface of the stamp body processed by exposure to ultraviolet rays.
In the case of such a conventional stamp making apparatus, an image of stamp characters is transferred from the ink ribbon to the printing paper ribbon, and hence an image of the stamp characters (engraved on the stamping face) of a stamp made by using the exposure mask of the ink ribbon, and an image of the stamp characters printed on the printing paper ribbon become identical to each other. On the other hand, in an image of an imprint of the stamp characters formed by using the stamp, images of individual characters are slightly bolder than those of the characters engraved on the stamping face of the stamp. That is, the images of the characters engraved on the stamping face are identical in boldness or thickness with those of the characters imprinted on the label affixed to the back surface of the stamp, but different from the images of the stamp characters imprinted by using the stamp. Particularly, to make a stamp limited in character width or a small-sized stamp, it is required to engrave or form characters on the stamping face in an even thinner typeface by taking into account defacing or broadening of images of stamp character imprinted by using the stamp. In such a case, the characters printed on the label affixed to the back surface of the stamp become very thin and difficult to read. Further, an imprint of stamp characters formed by using the stamp gives the viewer an impression different from one received from the printed stamp characters on the label affixed to the back surface of the stamp.